The informal, slightly tongue-in-cheek title given to a respected individual in the open source development community who sets general directions and makes final calls in certain situations within the scope of a given project. The BDFL is a tacit acknowledgement that communal, consensus-based decision making within the open source community occasionally runs up against obstacles, in which case a single authoritative voice can be useful. That BDFLs survive and flourish in these otherwise anarchistic contexts is attributed to their personal charisma and their reluctance to wield their power except in rare moments.

Of course, a project coordinator cannot really be anything like a dictator in the sense that he or she ultimately cannot enforce a decision, since a project fork is always possible.

Not all, or even most, open source projects have a BDFL.

Note the difference from the historical meaning of benevolent dictator, which is used in a political context.

List of Benevolent Dictators for Life

Blender
Ton Roosendaal

Drupal content management framework
Dries Buytaert

Linux kernel
Linus Torvalds, explicitly recognising the "benevolent dictator" epithet, e.g. in the interview published August 18, 2004 in Business Week

OpenBSD operating system
Theo de Raadt

Perl programming language
Larry Wall

PHP programming language
Rasmus Lerdorf

Python programming language
Guido van Rossum, known for his conservatism in changing Python. Very little changes between Python versions, and what does change tends to be considered and discussed for months or years in advance.

ReiserFS
Hans Reiser

Samba software
Andrew "Tridge" Tridgell

TTDPatch
Josef Drexler

Wikipedia
Jimbo Wales, who however is not convinced he can be qualified as a "benevolent dictator" since wikis require less centralized management than typical software projects.

WINE, the Open source implementation of the Windows API
Alexandre Julliard

Slackware, the most Unix-like Linux distribution, known for stability and speed.
Pat Volkerding

From Wikipedia, the free encyclopedia.

Our BDFL is so awesome. He is so relaxed and even asks for our input. He is the r0x0r!

Acronym: Band Dudes For Life. an accompaniment of death metal dudes from the Michigan metal scene, dedicated to all thing metal. To be BDFL is to be devoted to metal music, musicianship, lifestyle and culture.